feat(11.1-01): DB migration, API routes, schema type updates for agent initials storage

- Add agentInitialsData text column to users table (drizzle/0009_luxuriant_catseye.sql)
- Add 'agent-initials' to SignatureFieldType union in schema.ts
- Update isClientVisibleField() to exclude both agent-signature and agent-initials
- Create GET/PUT /api/agent/initials route with auth guard and 50KB size limit

teressa-copeland-homes/src/lib/db/schema.ts

@@ -7,7 +7,8 @@ export type SignatureFieldType =
   | 'text'
   | 'checkbox'
   | 'date'
-  | 'agent-signature';
+  | 'agent-signature'
+  | 'agent-initials';
 
 export interface SignatureFieldData {
   id: string;
@@ -34,7 +35,8 @@ export function getFieldType(field: SignatureFieldData): SignatureFieldType {
  * surface to the client as required unsigned fields.
  */
 export function isClientVisibleField(field: SignatureFieldData): boolean {
-  return getFieldType(field) !== 'agent-signature';
+  const t = getFieldType(field);
+  return t !== 'agent-signature' && t !== 'agent-initials';
 }
 
 export const users = pgTable("users", {
@@ -43,6 +45,7 @@ export const users = pgTable("users", {
   passwordHash: text("password_hash").notNull(),
   createdAt: timestamp("created_at").defaultNow().notNull(),
   agentSignatureData: text("agent_signature_data"),
+  agentInitialsData: text("agent_initials_data"),
 });
 
 export const documentStatusEnum = pgEnum("document_status", [